Control of Si-Based All-Dielectric Printing Color through Oxidation

Abstract

All-dielectric color printing by means of high-index Mie resonators has enabled wider control of reflection colors depending on structural geometry. However, modifying the geometry, including the height, by using conventional fabrication processes remains challenging, and drastic color modification approaches via the addition of a new tuning axis are required to extend color varieties and applications. Here, we demonstrate all-dielectric pixel color control through Si oxidation. Oxidized monocrystalline Si nanostructures exhibit wider tunability of brilliant reflection colors depending on the oxidation reaction. The different color change properties of each nanostructure enable the construction of an "invisible ink" that can hide color information. This approach for controlling printing color could be utilized to further extend color variation and reactive applications.

Multifunctional Dielectric Metasurfaces Consisting of Color Holograms Encoded into Color Printed Images

“…Since the cones are closely packed, changing the pixel size p shifts the resonance wavelength due to the coupling that exists between neighboring cones. This coupling originates from the fact that the inter-cone distance is comparable to the distance over which the fields extend from the cones [21] . From Figure 2d, it can be seen that the remainder of the visible spectrum can be covered by choosing p=340 nm and p=400 nm, while again varying r from 0.2p to 0.35p.…”

Full color generation with Fano-type resonant HfO2 nanopillars designed by a deep-learning approach

“…Although both plasmonic and alldielectric MSs can control the resonance properties by tuning the geometrical parameters [23][24][25] , the latter provide high-Q resonances as well as lower intrinsic Ohmic losses. Silicon (Si) as a high-refractive-index material in the visible range has been widely used in different patterned geometries such as square 26 , circular [27][28][29][30] and cross-shaped 31 nanopillars (NPs) to generate structural colors. However, Si suffers from high material losses for wavelengths smaller than 600 nm preventing generation of highquality colors.…”

Giant photothermal nonlinearity in a single silicon nanostructure

“…The sample was a single-crystalline Si nanoblock array on quartz (see Fig. 1a and fabrication detail in Methods), which has been demonstrated recently to host multipolar electric/magnetic resonances within a single unit 15 , 22 . Figure 1b is a scanning ion-beam microscope image of one Si nanoblock, showing the high-quality sharp edges and corners.…”